Online advertisers have often struggled with the problem of their advertisements (also written as “ads”) being ignored by their perceived target audiences. The target audiences often ignore the advertisements because they do not match their preferences. As a result, content providers and advertisers strive to make advertisements more relevant to individual users, i.e., to personalize advertisements.
One attempt to make advertisements more relevant involves serving advertisements based on the content of the web page a user is viewing, based on the premise that the user viewing the web page is interested in ads related to the subject matter of the web page. However, this solution tailors advertisements to the content of the web page, which does not necessarily reflect the individual actual user's preferences. Furthermore, there are content providers and advertisers who do not participate in services that serve advertisements based on page content, yet still have the problem of users ignoring their advertisements because of their perceived irrelevance.
The problems associated with tailoring advertisements to individual users are further heightened by concerns regarding privacy. Advertisement personalization often involves collection, retention, and sharing of personal information. Many users are wary of the privacy implications of these practices, and thus have objected to advertisement personalization.